[DevTools] Use inspector_protocol generator in content/browser/devtools.

content/browser/devtools/BUILD.gn

Index: content/browser/devtools/BUILD.gn
diff --git a/content/browser/devtools/BUILD.gn b/content/browser/devtools/BUILD.gn
index 2d457083e7ff95146fd62a190b6394198a9f1d9d..d0530555ae5bd732bdbb463d5868300e8e918b5f 100644
--- a/content/browser/devtools/BUILD.gn
+++ b/content/browser/devtools/BUILD.gn
@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 import("//tools/grit/grit_rule.gni")
+import("//third_party/inspector_protocol/inspector_protocol.gni")
 
 group("resources") {
   public_deps = [
@@ -33,6 +34,37 @@ grit("devtools_resources") {
   ]
 }
 
+inspector_protocol_generate("protocol_sources") {
+  visibility = [ "//content/browser" ]
+  deps = [
+    "//third_party/WebKit/Source/core/inspector:protocol_version",
+  ]
+  _blink_protocol_path =
+      rebase_path("$root_gen_dir/blink/core/inspector/protocol.json",
+                  root_build_dir)
+
+  inspector_protocol_dir = "//third_party/inspector_protocol"
+  out_dir = target_gen_dir
+  config_file = "protocol_config.json"
+  config_values = [ "protocol.path=$_blink_protocol_path" ]
+
+  inputs = [
+    "$root_gen_dir/blink/core/inspector/protocol.json",
+    config_file,
+  ]
+
+  # These are relative to $target_gen_dir.
+  outputs = [
+    "protocol/io.cc",
+    "protocol/io.h",
+    "protocol/forward.h",
+    "protocol/protocol.cc",
+    "protocol/protocol.h",
+    "protocol/tracing.cc",
+    "protocol/tracing.h",
+  ]
+}
+
 action("gen_devtools_protocol_handler") {
   visibility = [ "//content/browser" ]
   deps = [